Question 26:

• WAEC 2018

If \(\alpha\) and \(\beta\) are the roots of the equation \(2x^{2} + 5x + n = 0\), such that \(\alpha\beta = 2\), find the value of n.

A. -4
B. -2
C. 2
D. 4

Question 27:

• WAEC 2018

Solve \(\log_{2}(12x - 10) = 1 + \log_{2}(4x + 3)\).

A. 4.75
B. 4.00
C. 1.75
D. 1.00

Question 28:

• WAEC 2018

Find the coefficient of \(x^{3}\) in the binomial expansion of \((x - \frac{3}{x^{2}})^{9}\).

A. 324
B. 252
C. -252
D. -324

Question 29:

• WAEC 2018

The general term of an infinite sequence 9, 4, -1, -6,... is \(u_{r} = ar + b\). Find the values of a and b.

A. A = 5, b = 14
B. A = -5, b = 14
C. A = 5, b = -14
D. A = -5, b = -14

Question 30:

• WAEC 2018

If \(\begin{vmatrix} k & k \\ 4 & k \end{vmatrix} + \begin{vmatrix} 2 & 3 \\ -1 & k \end{vmatrix} = 6\), find the value of the constant k, where k > 0.

A. 1
B. 2
C. 3
D. 4